Quest timing - continuous party member or not

1) When a character leaves and rejoins, does their quest time reset or is it just added together.IE. I'm trying to do Hexxat's 'claw' quest, but had her leave and re join before it started. Has the one week timer for Cabrina to appear been reset or just missing the time Hexxat wasn't part of the team

2) What NPC events don't require party membership?For example once he starts, Edwin, does not need to be part of the team for the clock to count on the deciphering . Any others like this?